1. Field of the Invention
This invention generally relates to printing systems which print out text stored in a buffer. More specifically, this invention relates to a system for controlling the output printing of columns which have been stored in a buffer sequentially.
2. Description of the Prior Art
Representative of the closest known prior art are U.S. Pat. Nos. 3,351,917; 3,512,623; 3,739,344; 3,577,127; 3,609,699; and IBM Technical Disclosure Bulletin Vol. 9, No. 11, April 1967, pages 1575-1577. The first three listed patents were developed during a search of unexpired U.S. patents in the Patent Office. Although none of the cited patents is considered pertinent to the subject invention, U.S. Pat. No. 3,739,344 does disclose a printing system for aligning numbers against a tab stop. The carrier is caused to escape to the desired tab stop, and for each number keyed, the carrier is backspaced a distance equivalent to the escapement for the keyed number.
In the past there have been a number of ways of handling columns which have been stored sequentially and which are to be printed out in a side-by-side format. Generally this has been accomplished by defining the field in which each column is to be printed, printing a column in its entirety, and then reverse indexing and tabbing to the beginning of the next column to be printed. Not only has this been time consuming, but elaborate indexing and tabbing structure has been required. This is particularly the case when there is a difference in the length of each column. A need then arises for determining the extent of indexing to the beginning of the next column for printing. Another example of prior art handling of columnar printout is illustrated in the referred IBM TDB. Here the columns are keyed as they will be printed out. This can be disconcerting to the operator even in the absence of the required elaborate coding. The above problems are overcome with the subject system through marking the columns during input keying for storage and then controlling printout dependent upon the marking. In this way corresponding lines of each column are printed out on a print line automatically and sequentially prior to causing a printer carrier return.